Young Adult.

The Tiffany Aching books are a young adult subseries that spins off from the witches series. Very much worth reading even if you're not huge on YA stuff, especially since they essentially finish off the witches storyline.

As others have said "Young Adult," but they're not significantly different from the rest of the series imo. Protagonist in most is a child versus adults as in the rest of the books and they lack the off-color jokes and occasional swearing of the main series. Stories in the YA novels are about the same level of complexity as the others, and the violence is about the same, too.

One reader's opinion.